Knife sharpener



FIG. 1 is an upper perspective view of a knife sharpener showing my new design.

FIG. 2 is a cross-sectional view thereof taken along line 2-2 of FIG. 3.

FIG. 3 is a top view thereof.

FIG. 4 is a side view thereof.

FIG. 5 is an enlarged cutaway of a side view thereof.

FIG. 6 is a side view thereof with the guide members moved apart.

FIG. 7 is a top view of the knife sharpener of FIG. 6.

FIG. 8 is a side view of the knife sharpener with the guide members moved apart and a second guide member rotated; and,

FIG. 9 is a front view of the knife sharpener of FIG. 8 with a cross-section taken along line 9-9 in FIG. 8.

Any shading and cross-hatching are not features of the design but are utilized to illustrate the surface contours of the knife sharpener in the drawings. 

The ornamental design for a knife sharpener, as shown and described. 